At present, electronic and voltage characteristics of many kinds of newly manufactured electronic appliances need to be tested by a testing apparatus before the electronic appliances are shipped out from the factory. Many electronic appliances such as LCDs are becoming more compact and complicated with each new product release. Therefore testing of the electronic and voltage characteristics by a well-equipped testing apparatus is becoming more and more important. Typical tests that are carried out include input voltage, output voltage, output current, output loading, output power, output noise, power efficiency, high voltage/high current, short circuits, etc.
Generally, electrical safety standards are established and enforced in various countries in which the electronic appliances are sold and used. The safety standards apply in order to avoid dangers such as electrical shock, electrostatic discharge, heat convection, and electromagnetic radiation. Similarly, many electrical appliances need to pass high voltage testing (also known as hi-pot testing) and insulation resistance testing. Hi-pot testing uses either AC or DC stimulus voltages to test the capability of insulation and the capability of components such as capacitors to withstand high voltages. Examples of hi-pot tests include a high voltage test on phototriacs, a reverse high voltage test on transistors, a leak current test on high voltage capacitors, and an insulation test on insulating material. In another kind of hi-pot test, a live wire, a ground wire and a neutral wire are subjected to high voltage. It is common for a hi-pot testing apparatus to be implemented in the production line of a factory. With a hi-pot testing apparatus, the results as to the satisfactory condition or otherwise of electronic components of the electronic appliances are apt to be accurate.
FIG. 7 is a schematic diagram of conventional testing of an LCD. The LCD 100 to be tested is positioned on a conductive pad 102, and the conductive pad 102 is positioned on and electrically connected to a working table 104. A power port (not visible) of the LCD 100 connects with a hi-pot testing signal generator 101 via a connection line 103. A signal port (not visible) of the LCD 100 connects with the conductive pad 102 via a connection line (not visible). The working table 104 is grounded via a ground line (not labeled). The hi-pot testing signal generator 101 is also grounded. Therefore the hi-pot testing signal generator 101, the LCD 100, the conductive pad 102, the working table 104, and ground cooperatively form an electrical loop. The hi-pot testing signal generator 101 can generate testing signals, and transmit the testing signals to the LCD 100 via the connection line 103. The hi-pot testing signal generator 101 then receives feedback signals, and can thereby evaluate whether the LCD 100 complies with applicable safety standards.
An operator is needed to manually connect and disconnect the power port of the LCD 100 to and from the hi-pot testing signal generator 101, and to manually connect and disconnect the signal port of the LCD 100 to and from the conductive pad 102. This manual plugging and unplugging of the connection line 103 and the connection line (not visible) is unduly time-consuming and increases costs. In addition, the high voltage typically used by the hi-pot testing signal generator 101 presents a danger to the operator.
What is needed, therefore, is a device that can overcome the above-described deficiencies by providing automatic electrical connecting and disconnecting of products under test such as LCDs.